[CC} tunnelfacing

if not turtle then
    printError( "Requires a Turtle" )
    return
end

local tArgs = { ... }
if #tArgs ~= 1 then
    print( "Usage: tunface <length>" )
    return
end

-- Mine in a quarry pattern until we hit something we can't dig
local length = tonumber( tArgs[1] )

if length < 1 then
    print( "Facing length must be positive" )
    return
end

local depth = 0
local item = 1

local function count()
    length = length + 1
    if math.fmod(length, 10) == 0 then
        print( "Faced "..length.." section." )
    end
end

local function tryDig()
    while turtle.detect() do
        if turtle.dig() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

local function tryDigUp()
    while turtle.detectUp() do
        if turtle.digUp() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

local function tryDigDown()
    while turtle.detectDown() do
        if turtle.digDown() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

local function refuel()
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" or fuelLevel > 0 then
        return
    end

    local function tryRefuel()
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                turtle.select(n)
                if turtle.refuel(1) then
                    turtle.select(1)
                    return true
                end
            end
        end
        turtle.select(1)
        return false
    end

    if not tryRefuel() then
        print( "Add more fuel to continue." )
        while not tryRefuel() do
            os.pullEvent( "turtle_inventory" )
        end
        print( "Resuming Tunnel Facing." )
    end
end

local function charge()
    local function tryCharge()
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                if turtle.getItemDetail(n).name == "chisel:cobblestone2" then
                    turtle.select(n)
                    return true
                end
            end
        end
        turtle.select(2)
        return false
    end
    if not tryCharge() then
        print( "Add more cobblestone to continue." )
        while not tryCharge() do
            os.pullEvent( "turtle_inventory" )
        end
        print( "Resuming Tunnel Facing." )
    end
end

local function chargeTorch()
    local function tryChargeTorch()
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                if turtle.getItemDetail(n).name == "tconstruct:stone_torch" then
                    turtle.select(n)
                    return true
                end
            end
        end
        turtle.select(16)
        return false
    end
    if not tryChargeTorch() then
        print( "Add more torches to continue." )
        while not tryChargeTorch() do
            os.pullEvent( "turtle_inventory" )
        end
        print( "Resuming Tunnel Facing." )
    end
end

local function tryUp()
    refuel()
    while not turtle.up() do
        if turtle.detectUp() then
            if not tryDigUp() then
                return false
            end
        elseif turtle.attackUp() then
        else
            sleep( 0.1 )
        end
    end
    return true
end

local function tryBack()
    refuel()
    while not turtle.back() do
            sleep( 0.1 )
    end
    return true
end

local function tryDown()
    refuel()
    while not turtle.down() do
        if turtle.detectDown() then
            if not tryDigDown() then
                return false
            end
        elseif turtle.attackDown() then
        else
            sleep( 0.1 )
        end
    end
    return true
end

local function tryForward()
    refuel()
    while not turtle.forward() do
        if turtle.detect() then
            if not tryDig() then
                return false
            end
        elseif turtle.attack() then
        else
            sleep( 0.1 )
        end
    end
    return true
end

local function tryPlace()
    refuel()
    charge()
    while not turtle.detect() do
        if turtle.place() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

local function tryPlaceUp()
    refuel()
    charge()
    while not turtle.detectUp() do
        if turtle.placeUp() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

local function tryPlaceDown()
    refuel()
    charge()
    while not turtle.detectDown() do
        if turtle.placeDown() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

local function tryPlaceTorch()
    refuel()
    chargeTorch()
    while not turtle.detectDown() do
        if turtle.placeDown() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

print( "Facing the tunnel..." )

for n=1,length do
    tryDig()
    tryPlace()
    tryUp()
    tryDig()
    tryPlace()
    tryUp()
    if math.fmod(n, 7) == 0 then
        tryPlaceTorch()
    end
    tryDig()
    tryPlace()

    turtle.turnRight()
    turtle.turnRight()

    tryDigUp()
    tryPlaceUp()
    tryForward()
    tryDigUp()
    tryPlaceUp()
    tryDigDown()
    tryForward()
    tryDigUp()
    tryPlaceUp()

    tryDig()
    tryPlace()
    tryDown()
    tryDig()
    tryPlace()
    tryDown()
    tryDig()
    tryPlace()

    turtle.turnRight()
    turtle.turnRight()

    tryDigDown()
    tryPlaceDown()
    tryForward()
    tryDigDown()
    tryPlaceDown()
    tryForward()
    tryDigDown()
    tryPlaceDown()

    turtle.turnRight()
    tryForward()
    turtle.turnLeft()

    if n == length then
        print( "Tunnel facing complete." )
    end

end

print( "Tunnel facing complete." )
print( "Faced "..length.." segments total." )